ES2640973T3 - Method of manufacturing a needle and needle - Google Patents

Abstract

A method of forming a characteristic element in a cannula in a predetermined fixed fixed position immutable along the length of the cannula, comprising: providing a cannula (10) having a first end (11), a second end (12) , an axis (13), a length that extends from the first end to the second end, and an outer diameter that extends over at least a first portion of the length; characterized by the steps of: providing a sleeve (40) with a proximal flange (144), a distal flange (145), an inner diameter, extending a sleeve length (47) from the flange proximal to the distal flange, and extending about edges from the flange proximal to the distal flange, thus forming a slit (50) extending in a direction of length of the sleeve, in which the sleeve (40) has an inner diameter smaller than the outer diameter of the first portion of the cannula; placing the sleeve (40) on the cannula (10) in the first portion of the cannula in an interference fit such that the slit (50) expands to accommodate the cannula; and attach the sleeve to the cannula with an additional mechanical connection (60).

Description

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DESCRIPTION

Method for manufacturing a needle and needle Field of the Invention

The object of the invention is related to the field of perfusion therapy. In particular, the invention is related to an introducer needle having a flange disposed at a predetermined distance from the needle tip, and to a method of manufacturing such a needle.

Background of the Invention

Catheters, particularly intravenous (IV) catheters, are used to perfuse a fluid, such as a normal saline solution, various medications and total parenteral nutrition, in a patient or to withdraw blood from a patient. Peripheral IV catheters tend to be relatively short and are of the order of approximately 38.1 mm (1.5 inches) in length. The most common type of IV catheter is a peripheral IV catheter over the needle. As the name implies, a catheter over the needle is mounted on an introducer needle that has a pointed distal tip. The catheter and the introducer needle are mounted so that the distal tip of the introducer needle extends beyond the distal tip of the catheter, the needle bevel oriented so that it separates from the patient's skin.

The catheter and introducer needle assembly is inserted at a small angle through the patient's skin inside the peripheral blood vessel, that is, a smaller blood vessel that is not directly connected to the heart, but is one of the branches of the central blood vessels that connect directly to the heart. In order to verify the proper placement of the assembly in the blood vessel, the weather technician confirms that there is a return of blood in the needle and in a return chamber located at the proximal end of the needle, which typically is formed as part of the needle hub. Once the proper placement has been confirmed, the weather technician applies pressure to the blood vessel by squeezing the patient's skin over the distal tip of the introducer needle and the catheter. Finger pressure obstructs any additional blood flow through the introducer needle. The weather technician removes the introducer needle, leaving the catheter in place, and attaches a fluid handling device to the catheter hub. Once the introducer needle has been removed from the catheter, it is a “pointed element contaminated with blood”, and must be handled properly.

In recent years there has been great concern regarding the contamination of the chemical technicians with the blood of a patient and an acknowledgment that "pointed elements contaminated with blood" should be discarded immediately. This concern has occurred as a result of the occurrence of diseases that are currently incurable and fatal, such as the Acquired Immunosuppressive Deficiency Smdrome ("AIDS"), which can be transmitted by exchanging body fluids from one infected person to another person. In this way, contact with the body fluid of a person infected with HIV should be avoided. As indicated above, if an introducer needle has been used to place a catheter in the vein of a person infected with HIV, the introducer needle may be a vehicle for disease transmission. Although the chemical technicians are aware of the need to properly handle the “pointed elements contaminated with blood”, in certain medical environments, such as emergency situations or as a result of lack of attention or care, needle sticks with needles can occur contaminated introducers.

As a result of the problem of accidental needle sticks with "pointed elements contaminated with blood", different needle protectors have been developed. Examples of such protectors are shown in U.S. Patent No. 6,004,294 and in U.S. Patent Application No. 09 / 717,148 (filed November 21, 2000). These protectors work by the application of a characteristic element, such as a portion of the enlarged diameter, formed on the needle. The application means can take many forms, such as an elastic gate forced to come into contact with the enlarged portion of the needle diameter when the needle tip is inside the shield. Due to the small size of the needle and its delicate structure, it has been difficult to provide a characteristic element that can withstand adequate force without affecting the operation of the needle itself. In addition, such characteristic elements have traditionally included a ramp, a radiated or angled surface that extends from the surface of the needle, which may create difficulties in capturing the tip inside the shield or that may cause a force to be exerted on the needle in a non-axial direction.

A method that corresponds to the preamble of claim 1 is disclosed in WO 01/68174.

GB 472.952 A describes a medical needle that supports a split sleeve that surrounds the needle shaft. The bushing is surrounded by a sleeve provided with an adjustment screw or other fastening means, whereby the bushing is precisely attached to the shaft. By this means, the operator can precisely predetermine the depth of the needle thrust. To do this, the bushing must be positioned correctly by the operator. The cap is not a fixed part of the needle.

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Summary of the Invention

It is an object of the present invention to provide a method for manufacturing a needle that can be used with various protective devices designed safely.

The method of forming a characteristic element in a cannula, according to the invention, is defined by claim 1.

It is an advantage of another aspect of the invention to provide a method for manufacturing a needle having a characteristic element with a right angle flange.

It is an advantage of another aspect of the present invention to form a needle with a sleeve secured to a cannula in a predetermined place and a method of securing the sleeve to the cannula in the predetermined place.

An advantage of yet another aspect of the present invention is to provide a technique for securing a characteristic needle element that has a pointed flange at right angles that can be easily captured by means of application on a needle guard, and once captured. , can direct the forces from the means of application to the needle in a substantially axial direction.

According to one aspect of the invention, a method is provided for forming a characteristic element in a needle. In particular, a hollow metal cannula has a first end and a second end, and a substantially constant outer diameter extending over at least a portion of its length. An annular metal sleeve having a proximal flange and a distal flange is provided. The length of the annular sleeve is less than the length of the constant diameter portion of the cannula. The sleeve has an inner diameter approximately equal to, or less than, the outer diameter of the constant diameter portion of the cannula. Two edges extend axially along the length of the sleeve, from the proximal flange to the distal flange, thereby defining a slit. The sleeve is located on the cannula in the constant outer diameter portion in an interference fit. An additional mechanical joint is provided to secure the sleeve to the cannula. For example, the sleeve can be welded to the cannula using a laser welder on at least one edge of the sleeve near any one of the proximal face or the distal face. In addition, the sleeve may alternatively be crimped or glued to the cannula. According to another aspect of the invention, a needle that has been made according to this method is provided.

Certain embodiments of this aspect of the invention make the proximal flange perpendicular to the axis of the cannula or that the distal flange is perpendicular to the axis of the cannula. The sleeve can be welded to the cannula in a position close to both proximal and distal faces, or a seam weld can be applied along the length of the sleeve. In addition, the sleeve may alternatively be crimped or glued to the cannula. The sleeve can be formed by rolling a metal sheet in an angular shape, such as a cylinder, and then sliding it over the cannula. A window can be formed in the sleeve in a predetermined position with respect to the slit and the sleeve can be welded to the cannula in the window. Such a window can be arranged in the sleeve in a 180 ° position of the slit.

Certain implementations of this aspect of the invention assume that the sleeve is welded to the cannula after crimping or that an adhesive is used to attach the sleeve to the cannula. The use of an adhesive can be particularly advantageous for holding the sleeve in place before forming the crimping or welding.

Brief description of the drawings

Figure 1 is an exploded perspective view of a cannula and a sleeve according to an aspect of the invention.

Figure 2 is a perspective view of a cannula and a sleeve according to an aspect of the invention with a seam weld.

Figure 3 is an exploded perspective view of a cannula and a catheter on the needle, in accordance with an aspect of the invention.

Figure 4 is a cutaway side view of the cannula and catheter of Figure 3.

Figure 5 is a perspective view of a cannula and a sleeve according to another aspect of the invention.

Figure 6 is a side elevation view of the cannula and sleeve of Figure 5.

Figure 7 is a top elevational view of a cannula and a sleeve according to another aspect of the invention.

Figure 8 is a bottom elevation view of the cannula and sleeve of Figure 7.

Figure 9 is a perspective view of an insulated sleeve.

Figure 10 is a front elevation view of the sleeve of Figure 9.

Figure 11 is a side elevational view of the sleeve of Figure 9.

Figure 12 is a top elevation view on a sheet used to form the sleeve of Figure 9.

Figure 13 is a top elevational view of a cannula and a sleeve according to an aspect that is outside the scope of the invention.

Figure 14 is a side elevational view of the cannula and the sleeve of Figure 13.

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Figure 15 is a cutaway side view of the cannula and sleeve of Figure 13.

Figure 16 is a perspective view of a sleeve for use in accordance with aspects of the

invention.

Detailed description

As used herein, the term "proximal" refers to a position in needle 1, which, during normal use, is closest to the weather technician using the device and the furthest from the patient in connection with which the device is used (right side of figure 4). In contrast, the expression "distal" refers to a position in the needle, which, during normal use, is the furthest from the weather technician using the device and the closest to the patient in relation to which the device is used. device (left side in figure 4).

At various stages of the manufacture of the needle assemblies and during the use of the needles, it will be advantageous to have a distinctive feature in the needle 1 that is secured in a fixed position and that is oriented with respect to the rest of the needle 1, particularly the tip 14. For example, a characteristic element of this type could be used to orient the needle 1 with respect to a hub or needle holder. As a consequence, the tip 14 of the needle will also be in a fixed orientation with respect to the fastener. The healthcare provider immediately knows in this way the orientation of the tip 14 of the needle simply by grasping the fastener. In addition, such a characteristic element is more easily grasped by machines designed to automatically manufacture needles and catheter assemblies on the needle. The characteristic element could be used to apply to a strip 101 in a catheter 100 (see Figure 4), whereby the needle is positioned in a particular position inside the catheter and it is guaranteed that the tip 14 of the needle extends outside the catheter a satisfactory distance. In addition, such a feature can be more easily grasped by a safety device designed to capture the tip 14 of the needle after use.

According to one aspect of the invention, a needle 1 includes a cannula 10 having a sleeve or sleeve 14 attached in a predetermined fixed position along the length of the cannula. As will be discussed more fully below, the sleeve 40 is preferably sized with an inner diameter that is smaller than the outer diameter of the cannula. As a consequence, there is an interference fit between the sleeve 40 and the cannula that helps keep the sleeve in its predetermined position. Additional mechanical joints or links 60 can be provided to better maintain the sleeve 40 in its position. With the sleeve 40 in position, the needle 1 includes a feature (which may include the proximal flange 44 and / or the distal flange 45 of the sleeve, or the same sleeve, or some other structure attached to or integrally formed with the sleeve, such as an appendix 80) that can be used for different purposes related to the manufacture and use of the needle 1. For example, once formed, the needle 1 can be inserted inside a catheter 100 for insertion into the tissue of a patient. After use, the needle 1 can be removed from the catheter. Next, the tip 14 of the needle can be captured inside a protective device designed for safety that seizes the characteristic element, as disclosed in US Patent No. 6,004,294 and in US Patent Application Number 09 / 717,148 incorporated herein by reference.

The cannula 10 includes a proximal end 11 and a distal end 12 extending along an axis 13. Typically, the cannula has a cylindrical shape. Preferably, at least one portion 21 of the cannula has a constant outside diameter. A beveled tip 14 is located at the distal end of the cannula. The beveled tip may be formed by two beveled surfaces, a proximal bevel 15 and a distal bevel 16 (see Figure 2), which are arranged at different angles with respect to the axis of the cannula to facilitate the introduction into the vein of the patient. The cannula includes an outer surface 20 and an inner surface 19. The inner surface 19 defines a central cavity 17 extending from the proximal end of the cannula to the distal end, forming a tip opening 23 at the distal end.

A flush opening 18 is located in the wall of the cannula 10, creating a fluid flow path from the central cavity 17 to the outside of the cannula within the catheter 100. Preferably, the flush opening is proximal to the sleeve 40. The catheter It is operatively applied to a flush chamber 90. The flush chamber can simply be the annular space around the needle inside the catheter (see Figure 4) or a separate chamber located in the needle hub. During use, this flow path provides the health care provider with a visual indication that the vein has been successfully penetrated because a small amount of blood circulates through the tip opening, through the flush opening and inside the flush chamber where it is visible to the healthcare provider. As shown in Figure 4, the catheter is transparent so that the blood in the annular space 90 is visible to the health care provider.

The bushing or sleeve 40 preferably has a substantially cylindrical shape (see Figure 9) formed by an outer surface 42, an inner surface 43 and a length 47 extending from a distal face 145 to a proximal face 144. The inner surface 43 defines an internal cavity 51. Importantly, according to certain practical embodiments of the invention, the sleeve 40 is sized to fit tightly over the cannula in an interference fit. The length 47 of the sleeve 40 preferably is not longer than the length of the constant diameter portion 21 of the cannula. As can be seen in Figure 4, when the sleeve 40 is located on the cannula, the distal face forms a distal flange 45 and the proximal face forms a flange

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proximal 44. Preferably, the distal flange and the proximal flange are perpendicular to the outer surface of the cannula 10 and to the axis 13 of the cannula.

A slit 50 is formed in the sleeve 40 and is defined by two edges 41. Preferably, the slit extends axially along the sleeve 40 from the proximal face 144 to the distal face 145. The slit may also have other shapes and still practice the invention In particular, the slit may extend around the sleeve 40 in a spiral shape or in other curved shapes. Before placing the sleeve 40 on the cannula, the edges are adjacent, or almost adjacent (see Figure 5). When the sleeve 40 is forced on the cannula, the edges are separated to accommodate the larger outer diameter of the cannula inside the internal cavity 51.

The sleeve 40 may be formed in any way, such as by extrusion, casting or the like. If the sleeve 40 is initially formed as a complete cylinder, the slit 50 can be formed in the sleeve, such as by means of cutting, burning, and others. In a practical embodiment of the invention, the sleeve 40 is formed by a flat plate 46 (see Figure 12). The sheet is laminated in an almost cylindrical shape, leading the edges to be joined and thus forming the slit. The sheet is sized so that the slit extends over less than 180 ° arc along the diameter of the sleeve when the sleeve is located on the cannula. Preferably, the slit extends over 20 ° of arc or less when the sleeve is located on the cannula. It will be appreciated that the slit may be larger or smaller and that the invention can still be practiced. Also, in certain practical embodiments, the slit may be formed as a groove disposed in the sleeve 40 that does not extend completely through the sleeve 40 radially (that is, the edges are connected by a thin tape before mounting the sleeve on the cannula).

Once the sleeve 40 has been formed, it slides over the distal end 12 of the cannula 10 and is placed in a certain position on a portion 21 of constant diameter of the cannula. Preferably, the sleeve 40 is located at a distance from the tip 14 so that the tip and the sleeve can be secured inside a shield after use, as explained in US Pat. No. 6,004,294, incorporated in this document by reference, and in the US Patent Application serial number 09 / 717,148, incorporated herein by reference. It will be appreciated that sleeve 40 may be located in other positions and still practice aspects of the invention. In addition, the sleeve 40 may be formed in other ways and be placed on the cannula in different ways and still practice aspects of the invention. For example, the flat sheet 46 may be laminated directly on the cannula and secured in its position as explained herein.

As explained above, the diameter of the inner cavity 51 of the sleeve 40 is preferably smaller than the diameter of the outer surface 20 of the cannula 10, creating an adjustment for minimal interference between the sleeve and the cannula. The edges 41 of the sleeve 40 are forced to separate to accommodate the outer diameter of the cannula. If the tape comes into contact with the edges, it breaks when the cannula is forced into the inner cavity. In any case, there is preferably a direct contact between the inner surface 43 of the sleeve 40 and the outer surface 20 of the cannula when the sleeve is placed on the cannula.

Adjustment by interference between the inner surface 43 of the sleeve 40 and the outer surface 20 of the cannula prevents movement of the sleeve 40 along the length of the cannula under certain loads. Certainly, the interference fit itself can provide adequate resistance to the movement of the sleeve 40 for a particular application, so that the interference fit can be considered as a suitable mechanical joint. However, in certain circumstances a greater resistive force will be desired. In these circumstances, an additional mechanical union 60 is provided, securing the sleeve 40 to the cannula. For example, sleeve 40 can be welded to the cannula using a laser welder. As shown in FIG. 2, a laser beam 301 of a laser welding device 300, such as a Nd: Yag laser welder, model Luxstar LX50 can be directed to the contact points in the sleeve 40. The sleeve and cannula are in direct physical application at contact points. A seam weld 160 can then be created along the slit 60 by supplying a laser beam at a series of points over the length of the sleeve.

Other welding techniques can also be used. Referring to Figures 7 and 8, two of the contact points or weld points 61 are located along the edges 41 in the slit 50, one near the proximal flange 44 and the other near the distal flange 45. The laser beam is directed to the junction of the edge and the cannula in the slit. The laser melts the material of the sleeve 40 and the cannula, which, in turn, cools to form an integral weld with the sleeve 40 as well as with the cannula, securing them with each other. Two other contact points or solder points 64 are arranged on the opposite side of the sleeve 40, 180 ° from the slit. Again, these welding points are arranged near the proximal flange 44 and the distal flange 45. The laser beam is directed to the outer surface 42 of the sleeve 40, melting through the wall of the sleeve so that the beams melt at least some portion of the outer surface 20 of the cannula 10. The molten portions of the sleeve 40 and the cannula 10 are cooled to form an integral weld with the sleeve, as well as with the cannula, securing them with each other.

These four welds can be created by dividing a single laser beam into four beams, and applying them to the desired welding points for a controlled period of time, which depends on the dimensions and the

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materials forming the sleeve 40 and the cannula 10, as well as the desired strength of resistance that must be supported by the mechanical joint 60. It will be appreciated that other welding techniques, in particular other laser welding techniques, can be used and still practice aspects of the invention. For example, welding can be provided in positions other than the slit. Currently, in a preferred application of the invention, two seam welds 160 formed 180 ° from each other are formed, none of which is located along the slit. The laser beam is supplied to the surface of the sleeve and produces a weld, which joins the sleeve to the cannula along both seams. Alternatively or additionally, a window 48 can be provided in the sleeve. The mechanical joint 60 can be formed by spot welding at the edge of the window (see Figures 3 and 4).

The dimensions and materials of the sleeve 40 and the cannula 10, as well as the operation of the laser welder, will depend on the particular application for the needle 1. It is preferred that the sleeve 40 and the cannula be formed of a similar alloy to ensure that a satisfactory mechanical union be formed by laser welding or other mechanical union. In an application of the present invention, the cannula is made of completely hard stainless steel 301 (or 302) and has an outside diameter of between 0.17 mm and 2.03 mm (0.007 and 0.080 inches) (including approximately 1.4 mm (0.055 inch)). The sleeve 40 is formed of a completely hard stainless steel plate 301 (or 302) approximately 0.05 mm (0.002 inches) thick and approximately a length of 1.27 mm (0.050 inches). The weld points are preferably about 0.12 mm (0.005 inches) inwards from the proximal and distal flanges. More preferably, the sleeve 40 comes into contact with the cannula where welding is applied. In any case, it is preferred that there is a gap not exceeding 0.025 mm (0.0010 inches) at a desired weld point. The laser beam is applied to the welding points for a period of 0.2 seconds at 100 Hz, and with a power of 30-50 KW. The resulting weld at the weld point is approximately 0.25 mm (0.010 inches) in diameter and can withstand an axial force of approximately 13.6 kg 22.7 kg (30-50 pounds).

Referring to Figures 13-15, another form of mechanical union is revealed. Crimping notches 70 are formed in the cannula in desired positions, such as in the otherwise constant diameter portion 21 of the cannula (constant, that is, excluding crimp notches). Preferably, the crimped notches do not penetrate the cannula wall. However, the crimped notches 70 may be formed as cutouts in the cannula wall. In addition, the flush notch 18 can be used as a crimp notch. The number, position and shape of the crimping notches 70 can be selected based on the particular application of the needle. For example, two crimping notches can be used, arranged on opposite sides of the cannula in a position distal to the flush notch 18 (see Figure 15). The sleeve 40 is formed and slides over the cannula until it is arranged directly on the crimp notches, capturing the crimp notches inside the inner cavity 51. Next, the sleeve 40 is crimped into the crimp notches. 25, creating a mechanical application at junction 63 between the sleeve and the cannula. The sleeve 40 can also be secured to the cannula using an adhesive material 62 or weld points 61. The use of an adhesive material can be advantageous, particularly to keep the sleeve in position in the cannula until the crimping or welding is completed. .

As discussed above, the characteristic element in the needle 1, such as the sleeve 40, and / or its proximal and distal flanges, are preferably symmetrical with respect to the axis of the catheter. It will be appreciated that sleeve 40 may have other forms and still practice the invention. For example, appendages or ribs 80 (see Figure 16) may be formed in sleeve 40, extending radially outwardly or extending axially from the distal flange or proximal flange along the surface of the cannula. Such appendages or nerves can be used to orient the cannula (and, therefore, the tip 14 of the needle) with catheter 100 (and thus a bucket that is seized by the health care provider). In addition, such appendages or nerves can be used as a record to observe and control the orientation of the cannula during the manufacturing process. The appendages or nerves can also be designed to cooperate with different structures in a needle shield to better capture the tip 14 of the needle.

In addition, as explained herein, the cannula has a substantially cylindrical shape. It will be appreciated that the cannula may have other forms and still practice aspects of the invention. For example, the cannula may have an oval cross section so that the sleeve 40 contacts the cannula only along the main axis of the oval. Instead, the sleeve may be formed with an internal cavity that has an oval cross section so that it comes into contact with the outer surface 20 of the cannula on the minor axis of the oval. The mechanical joint can then be formed at those contact points, by welding, using an adhesive material 62 or by crimping the sleeve 40 into a sample in the cannula.

It is preferred that sleeve 40 actually comes into contact with the cannula at the weld point during welding. Such a contact is preferably achieved by adjustment by interference between the sleeve 40 and the cannula. However, it will be appreciated that the sleeve 40 may be sized so that there is no interference fit and practice aspects of the invention. For example, a welding material may be arranged around the cannula when the sleeve 40 slides into position before welding. Advantageously, a welder that also functions as an adhesive material can be used. If the inner diameter of the sleeve 40 is larger than the outer diameter of the cannula, there will be a gap between the cannula and the sleeve that could interfere with

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a satisfactory laser welding. To solve this difficulty in this situation, the sleeve 40 may be forced in a direction against the outer surface 20 of the cannula to achieve a point of contact where welding can be performed. In addition, other welding techniques may not require tight positioning of sleeve 40 and cannula to achieve satisfactory welding. In fact, under certain circumstances, the sleeve 40 may be thick enough that enough material can be melted by the laser welder in order to make a proper weld without affecting the integrity of the sleeve.

As explained herein, four spot welding points or two seam welding are used. Any number of welds and weld points can be used as required to achieve a satisfactory joint between the sleeve and the cannula for a given application. In addition, welding points and seams may be located in other positions and still practice aspects of the invention. For example, the sleeve 40 may be secured to the cannula with a single weld formed in the sleeve in any position, such as a position away from the slit. The welding point may be at the junction of the proximal flange and / or the distal flange with the outer surface 20 of the cannula. The weld may be a single contiguous line that extends axially along the entire length of the sleeve 40 or circumferentially around the diameter of the sleeve.

The sleeve 40 is preferably located along the cannula at a distal point of the flush notch 18. It will be appreciated that the sleeve may be located in other positions and still practice aspects of the invention. For example, the flush notch 18 may be located between the sleeve 40 and the tip of the cannula. Alternatively, the sleeve 40 may be located in application with, or partially covering, the flush notch 18. In addition, the slit may be oriented in different positions with respect to the flush notch 18 and practice aspects of the invention.

The proximal flange and the distal flange preferably form surfaces at right angles to the outer surface 20 of the cannula. It will be appreciated that the flanges may have different shapes and still practice aspects of the invention. For example, the flange may be provided with a cut in the surface of the cannula, creating a gap that can be applied to certain types of gripping mechanisms contained within protectors. In addition, the proximal face 144 and the distal face 145 may have curved or notched surfaces, depending on the particular application of the invention.

Although the invention has been described herein with reference to a needle 1 used with a peripheral catheter IV and a safety guard, it is understood that the invention is applicable to other needles, such as hypodermic needles, epidural needles and others. In addition, although this invention is satisfied by embodiments in many different forms, preferred embodiments of the invention are shown in the drawings and are described in detail herein. The scope of the invention is defined by the appended claims.

Claims (7)

5 10 fifteen twenty 25 30 1. A method for forming a characteristic element in a cannula in a fixed predetermined position immutable along the length of the cannula, comprising: providing a cannula (10) having a first end (11), a second end (12), a shaft (13), a length extending from the first end to the second end, and an outer diameter extending over the minus a first portion of the length; characterized by the steps of: providing a sleeve (40) with a proximal flange (144), a distal flange (145), an inner diameter, extending a sleeve length (47) from the proximal flange to the distal flange, and extending edges from the proximal flange to the distal flange, thus forming a slit (50) extending in a direction of sleeve length, wherein the sleeve (40) has an inner diameter smaller than the outer diameter of the first portion of the cannula; placing the sleeve (40) on the cannula (10) in the first portion of the cannula in an interference fit such that the slit (50) expands to accommodate the cannula; and attach the sleeve to the cannula with an additional mechanical joint (60). 2. The method of claim 1, wherein the mechanical joint is a weld. 3. The method of claim 1, wherein the sleeve (40) is crimped to the cannula (10). 4. The method of claim 1, wherein the mechanical joint is a seam weld (160) formed by a laser welder (300) that extends substantially over the entire length of the sleeve. 5. The method of claim 1, wherein the sleeve (40) is glued to the cannula (10) by an adhesive material. 6. The method of claim 5, further comprising crimping (70) the sleeve (40) to the cannula (10). 7. The method of claim 5, wherein the sleeve is welded to the cannula.